Adjust random seed of displacement textures
To get the equivalent of translating and scaling the texture space, you will need to use Object coordinates for the displace modifier.



This allows for displacement independent of the location of the object being displaced.

For example, using Global coordinates, let's say you want a rock to be in a certain location, but it is not being displaced in the way you want.
using global coordinates the rock can only be displaced in one way per location.

Using Object coordinates, you can adjust the displacement by moving the object being used as Texture coordinates without moving the actual rock.

If you then decide to move the rock but want to keep the way it is displaced, all you have to do is move both the rock and the Texture coordinate object.